Folding fins for rockets and missiles



Aug. 6, 1957 A. s. GouLD FOLDING FINS FOR ROCKETS AND MISSILES 2 Sheets-Sheet 1 Filed Feb.i6, 1953 INVENTOR. ALBERT S. GOULD BY .w/2.9;

a. MLM

ATTORNEYS Aug. 6, 1957 A. s. GoULD 2,801,587

FOLDING FINS FOR ROCKETS AND 4MISSILES Filed Feb. e. 195s 2 sheets-sheet 2 INVENTOR. ALBERT S. GOULD Bum 4 AJM ATTORNEYS United States Patent "FOLDING FINSFORROCKETS ND fMISSlILES .lbert'S. Gould,ilnyokern, Calif.

'Application February 6, '1953,serialfN0- :335,615

L1-Claims. (Cl. IGZ- 50) y(Grantedmaar Tine-iss, UfsrCo-de (19s2),-sec. 266) 7The -inventiondescribed herein may be manufactured Iandusedby lor'for theeGovernment rof the' United States `"f America for governmental purposes without the payment of'anyroyalties thereon ortherefor.

VAThis -invention'relates `to rockets `and more particularly "totimprovements in stabilizingfiins for same.

One of the objects of the' invention isV to' provide a novel multiple "iin 'construction for 4a rocket `which permits launching of the rocket'through alaunching tube with "he'ns in foldedposition.

Another'object is to provide anovel folding fin andex- 4haust nozzle construction.

Another object isto provide novel'mechanism for con- 'jointlyactuating the'fins totheirextended positions, utilizing the pressure in'therocket motor reaction chamber.

Anotherobject 'isto actuate the'ns to their extended positions by a fin opening force'resistingan acceleration f0rce,`b`othfof which arelproportional to the rocket `motor reaction chamber` pressure.

Another object is toprovide a folding fin construction which may :be readily employed in rockets of relatively small calibre.

Another 1object is to provide a zsirnplied folding iin '.construction'which may be feconomically mass produced.

:Other objects and many of the attendant advantages Tof .this invention will be readily appreciated as the same be fcomes better 'understood by `reference 1to the following fdetailed description when considered :inzconnection with the/accompanying drawings wherein:

Fig. 1 is a longitudinal-cross section of one form of rocket nozzle and 'n construction, showing the fins in folded position, Vltaken -on line `1-l1, Figs. 3 and 4, portt'ionsfbeing broken -awayan`de'other portions omitted;

Fig. 1A is a fragmentary view similar to Fig. 1, showing the ns in extended position;

Fig. 2 is 'a section taken on line 2 2, Fig. 1;

Fig. 3 is a rear elevation as viewed from plane 3 3, Fig. 1, a portion being broken away;

Fig. 4 is an enlarged side elevation of a detail, viewed in the direction of arrow 4, Fig. 1;

Fig. 5 is a section taken on line 5 5, Fig. 1;

Fig. 6 is a section taken on line 6 6, Fig. 1;

Fig. 7 is an enlarged side elevation of a fin retainer shown in Fig. 1;

Fig. 8 is a rear elevation of Fig. 7, as viewed in the direction of arrow 8;

Fig. 9 is a section taken on line 9 9, Fig. 8, showing the retainer associated with fragments of the tins, portions of the latter being broken away;

Fig. 10 is a rear elevation of an alternative form of the invention;

Fig. 11 is a fragmentary section taken on line 11-11, showing ya fin in folded position, and

Fig. 11A is a section like Fig. 11, showing a n in extended position.

Referring in detail to the drawing, and particularly Figs. 1 to 9, the subject of the invention comprises a cup-shaped member 20 which is secured tothe rear end of arocket motor tube 22 lin anysuitable manner, -this member forming th'e'rearvclosure for the. rocket motor andalso a support'for a plurality of angularly spaced nozzles 24, 24a, 2417, 24e. Acollar 26 is secured'fto member 20 by a plurality of screws 28 'and is provided with equiangularly spaced 'slots l30, 30a,53`0b, 30e which receive, respectivelyfthe base portions,'32, 32a, 32'b,f3`2c of fins 34, 34a, 34b, 34C. As best shown in Figs. 1, 2 and 4, apin '36, supported in aperture in memberx26 and extending through an aperture in base portion 32-.of"iin 34, pivotally supports thelatter on the rocket ffor movement in a planepassing through the longitudinal axis of the rocket. As will be apparent, 4fins (34a, 34b, 34care `pivotally connected to member 26 -in the same manner bypins 36a,`36b,'36c, respectively. 4 e

A cylinder 38 is rigidly .aixed to the-center of member 20 tand slideably carries a-piston 40 therein to one end of which is rigidly al`n`xed a cruciform member 42 having projecting `fingers 43, 43a, 4311, 43e. As best shown'in'FigfZ, member 42 is 4'shaped so that-it may slide in the spaces between Ythervarious nozzles. A cap 44having `apertures 46 extending therethrough is disposed on the innerA end of the cylinder. The piston is provided with a frustoconicl portion 48 and the vcylinder is provided with a bore 50 of similar shape, the purpose of which will subsequently appear.

The tins are of uniform width anduniformly decrease in thickness from their forward or base portions toward their rear or tip ends. .The side yfaces are beveled so'that Lthe leading and trailing edges are generally knife shaped.

vAs best shownin Fig. 5, the base portion of each lfinis .provided with a thinned portion 52 which .may bedisvposed in thespace Vbetween adjacent nozzles. The Yfront surface of thisportion forms a camming'abutment against which an associated .projecting iingerof-meniber 42 may engage. Y

` As best shown in'Figs. l, 7, V8 and 9, thefns are .pro -vided withnotches .S4 which vreceive a resilient circular wire member Y'56 which is disposed in a circular Vgroove 58 in an retainer "member l60. This member is also provided with Afour equiangularly spaced notches 62, each of which receivesa rear portion of a tin tip. As best shown Yin Figs. v1 andr, a notched rubber disk `64 uis disposed between the variousns and urges them outwardly, this urge being resisted bywire 56, engaging n notches T54, thus ,preventing unauthorized outward movement of thelins Member''tl'is constructedof electricalinsulat'ing material andis provided witha metallic Vcontact66. One end of alead wire68 is connected to this contact, the lead wire being trained through an aperture 70 in member 64 and thence through one of the nozzles Where its other end (not shown) connects with one end of a bridge wire of a squib disposed within the rocket motor, the other end of the bridge wire being grounded to the motor.

In the operation of the invention so far described, the rocket is disposed within a launcher tube which is slightly larger in diameter than the rocket. When the rocket is to be launched an electrical potential is applied between contact 66 and the rocket tube which causes current to flow through the bridge wire of the squib tiring the latter and igniting the propellant charge in the rocket motor. The nozzle blast blows away tin retainer 6i), and the pressure in the motor forces piston 40 and member 42 rearwardly thus tending to cam the fins outwardly. The tube, however, restrains this motion and the iins ride against the tube until the rocket has passed through its forward end. At this point, with the tube restraint no longer present, the piston moves to its rearward limit position, as Ishown in Fig. 1A, actuating the tins to their outward ight positions. Tapered portion 48 of the piston jams and locks in tapered bore 50, preventing retrograde move- A' j ment of the piston during 'rocket` decelerations.A The iins 3 are retained in their flight position, .as shown in Fig.; 1A,

l during rocket acceleration, since they' tend to' lreturn kto theirfolded position under-urge of'acceleration and aeroydynamic drag forces During rocket deceleration` they n still-retain this position due to aerodynamic' drag thereon. .f

The construction illustrated in Pigs. 10, 11, 11A is in i f 'all essential krespects the Asame as that previously described,

yzles formed in said rear wall land projecting rearwardly therefrom-11,.y ja piston mounted. lin, a cylinder rformed inte? grally. gwjith the rear walll of said kclosure member and;A -f y extending forwardly therefrom, said; pistonbeing `movable .in said cylinder by lgas pressure within the rocket motor `and having a portion thereof extending rearwardly through n l the principal difference being in the manner in Whichthe i tins are cammed lto -cvpenl position.l In the construction Iso 'far described ythe rear surface 45 of a iinger` of mem l `ber y42 engages surface 47 on a `iinl forcirigfthe latteroub` .f

wardly` until kthe parts :move to lthe position shown in Fig.:y 1A wherein corner 49 of aiinengages the outer sur- 1 face 51 of the iinger; yWith lthisA constractionl,.thelevery arm actin-g to .rotate the-iin 'is relatively short. In the construction shownin Figs.y y10,11 and 11A, afin con@ 1 tacts member 142 at a greater distance frorn'thefpivotal i axis of the' itin' and hence the lever arm. acting to rotate the nis' considerably greater. `As the iin is rnrwedoutfy ward and its initial inertia overcome, theA cammingaction.

` continues jin aman'ne'r similar: to the first described emf lbodiment,r that is, with a relatively kshorter lever arm.; When the parts reachl theA positionl shown fin .Fig 151A,l the outer tip' of. 'a 'finger is vdisposed vin a notch lof a l `rfinl which latches lthe partsl against retrograde movement'.

What is claimed is:

` y l l. lIn a rocket motor` a cup lshaped closure -member adapted to be secured lto the rear end of rsaid rocket and having ka` rear' wall, ysaid closure `member having .exit` means for the discharge'of propellant gases frornsaid,y f A rocket; a `plurality otiin's pivotally mounted onthe rear l wall tot. said: closurey member for `angular* rotation from l a rearwardly folded positiong toA a forwardly open posi'f tion,` each of said tins having an exposed lateral surface on the forward end thereof, and an actuator for said pivotally mounted ns interposed between the end wall of said closure member and the lateral end surface of each of said tins for abutting engagement therewith, and means operated by the internal gas pressure of said rocket motor for transmitting longitudinal movement to said actuator, the said actuator having slidable abutting engagement with the end surface of said tins whereby to cause the angular rotation of said iins about said pivot to decrease with the longitudinal movement of said actuator.

2. In a foldable iin stabilized rocket, a cup shaped member adapted to be secured to the rear end of said rocket and having a rear wall, a plurality of exhaust nozsaid rear wall, a lplurality.ofzoutwardiy radially projectl ling iingersl eachy secured to said extending portion of said piston yfor actuating said fins, said ngers .being in inter-` digital `relation with the projecting portions ofsaid nozzles, f l

1 each of said iingers having a lateral rearwardly exposed Asurface and terminating in an outer end surface` substan` f tially equidistant from lthe longitudinal axisk of said piston,

lthe said lend surface forming acamming corner with the lateral rearwardly exposed surface of.said inger,a p1u f y rality of substantially rectangularly shaped .tins correspond- Y.

ingin numbersjtosaid fingers, means pivotally mounting f l cach of said'ns totherear -wall .of `said closure. member i l v at the outer forward lcorner; thereof, each n having a iforwardly lfacing surface in abutting relation with the said 1 f l lateral surface of arespective one of saidngers, the Kfor.-y y l y wardly facingA surface of said ffins. being adapted to be 1 `slidably andicammingly engaged by said camming corner? f .whereby the angular rotation of ksaid decreaseswith'r a the' linear rearward movement .of said lingers jin rotating saidns about said pivot from a rearwardly folded posiv-y f y3'.l Thecombinationdesenbed in claim 2 above wherein l .the forwardlyy facing surface of each of said :fins lterA lminates at its inner endin .aheeladapted to; be. engaged y l y by lthe louter end surface .otsaid finger near the endet i travel .thereof `to lock said tins against retrograde move .ment during the flight of saidrocket. p

' 4. The combination; describedl in claimy wherein said y i y pistonfis jturther .modieby the addition of means for arnming `the piston in the .cylinder whenthepiston has l moved tothe rearward limit of its motion.

`UN1TED` STATES PATENTS Great Britain Mar. 15, 1950 i l .iffyReterenees Citedin therfrleofthispatcnt.,l 

